A tunnel may be an artificial underground passage, (e.g. one built through a hill or under a tunnel, road, and/or river, etc.). The tunnel may be substantially horizontal and have a ratio of the length of the passage to the width of at least 2 to 1. In addition, the tunnel may be completely enclosed on all sides, and the openings may be saved for the length of the covered area causing limited accessibility to the tunnel. In a case of an emergency situation of a tunnel, emergency personnel may be deployed on-site of the structure to alleviate the emergency situation through mitigating a source of hazard as well as rescuing stranded civilians from the tunnel. The emergency situation may include events such as a fire, a chemical attack, terror attack, subway accident, tunnel collapse, and/or a biological agent attack.
In such situations, breathing air inside the tunnel may be hazardously affected (e.g., depleted, absorbed, and/or contaminated). In addition, flow of fresh air into the tunnel may be significantly hindered due to the tunnel having enclosed regions, lack of windows, and/or high concentration of contaminants. As a result, inhaling air in the tunnel may be extremely detrimental and may further result in death (e.g., within minutes). Furthermore, emergency work may often need to be performed from within the tunnel (e.g., due to a limitation of emergency equipment able to be transported on a ground level).
The emergency personnel's ability to alleviate the emergency in an efficient manner may be adversely affected by the lack of breathing air and/or the abundance of contaminated air. A survival rate of stranded civilians in the tunnel may be substantially decreased due to a propagation of contaminated air throughout the tunnel placing a large number of innocent lives at significant risk.
As such, the emergency personnel may utilize a portable breathing air apparatus (e.g., self-contained breathing apparatus) as a source of breathing air during a rescue mission. However, the portable breathing air apparatus may be heavy (e.g., 20-30 pounds) and may only provide breathing air for a short while (e.g., approximately 15-30 minutes). In the emergency situation, the emergency personnel may need to walk and/or climb to a particular location within the structure to perform rescuing work due to inoperable transport systems (e.g., obstructed walkway, elevators, moving sidewalks, and/or escalators, etc.). As such, by the time the emergency personnel reaches the particular location, his/her portable breathing air apparatus may have already depleted and may require running back to the ground floor for a new portable breathing air apparatus. As a result, precious lives may be lost due to precious time being lost.
An extra supply of portable breathing air apparatuses may be stored throughout the tunnel so that emergency personnel can replace their portable breathing air apparatuses within the tunnel. However, supplying structures with spare portable breathing air apparatuses may be expensive and take up space in the structure severely handicapping the ability of emergency personnel to perform rescue tasks. Furthermore, the tunnel may not regularly inspect the spare portable breathing air apparatuses. With time, the spare portable breathing air apparatuses may experience pressure loss placing the emergency personnel at significant risk when it is utilized in the emergency situation. The spare portable breathing air apparatuses may also be tampered with during storage. Contaminants may be introduced into the spare portable breathing air apparatuses that are detrimental to the emergency personnel.